This application was published in English on Jun. 22, 2000 as International Publication Number WO 00/35774.
This invention relates to a container of the type described in the preamble of the main claim. Such a container is known from FR-A-2690142.
This known container comprises an inner space in which a fluid to be dispensed is included, in which inner space a pressure vessel is included with pressure control means. In the pressure vessel, a first chamber is formed into which a gas has been introduced under relatively high pressure, while an outflow opening is provided which is closed by a closing member. This closing member is somewhat rod-shaped and is surrounded in the outflow opening by an O-ring in tightly sealing engagement therewith. In the rod-shaped element, a circumferential groove is provided. In the pressure vessel, opposite the first chamber, a second chamber is formed which is closed on the side proximal to the first chamber by a membrane to which the rod-shaped element is attached through one end thereof. In the second chamber, a control pressure has been applied by means of a gas. Between the first and the second chamber, a third chamber is included, through which the rod-shaped element extends and which is provided with an opening which forms a fluid connection between the third chamber and the inner space of the container.
When in this known apparatus in the third chamber a desired pressure prevails, for instance equal to the control pressure, the groove is located in the third chamber and the outflow opening is closed by the rod-shaped element. When fluid is dispensed from the inner space, the pressure therein will decrease, which results in a corresponding pressure decrease in the third chamber. As a result, the membrane-shaped wall part of the second chamber will deform in the direction of the first chamber, thereby moving the rod-shaped element axially, further into the first chamber. When the groove has been moved to the level of the O-ring, gas can escape under pressure from the first chamber via the groove past the O-ring to the third chamber and from there to the inner space of the container. As a result, the pressure in the third chamber rises, such that the membrane-shaped wall part is deformed back, against the control pressure, thereby moving along with it the rod-shaped element from the first chamber. When the rod-shaped element is sealingly embraced again by the O-ring, no gas can escape from the first chamber anymore, in which condition the pressure in the third chamber and in the inner space is approximately equal again to the desired pressure, in this case the control pressure.
This known container has as a disadvantage that already when fitting the pressure control, a control pressure is to be provided in the second chamber, and, moreover, the control means will operate the closing member directly, so that gas will flow out of the first chamber. The reason is that when fitting occurs under normal pressure, the pressure in the third chamber will always be lower than the control pressure in the second chamber. In order to obviate this problem, it has been proposed to mount the pressure control device and fill the container under excess pressure, such that the control pressure is compensated. This, however, is technically complicated and disadvantageous.
The object of the invention is to provide a container of the type described in the preamble, in which the disadvantages mentioned are obviated, while maintaining the advantages thereof. To that end, an apparatus according to the invention is characterized by the features according to claim 1.
In an apparatus according to the present invention, the advantage is achieved that prior to use the control means is at least functionally uncoupled from the closing member. This means that at a pressure in the third chamber which is relatively low with respect to the control pressure, for instance during assembly and filling of the container, movements of the control means will not force the closing member into an opened position. This means that prior to use the closing member will remain closed at all times. Only when a specific activation step is carried out is a functional coupling obtained between the control means and the closing member, such that a control pressure desired during use is obtained in the second chamber and upon decrease of the pressure in the third chamber relative to the control pressure, the closing member can be urged to the open position for the desired pressure fluid, as described in the introduction. The activation step is then to be carried out deliberately in order to set the pressure control into operation.
A pressure control for use in an apparatus according to the present invention further has the advantage that it can be readily stored and transported, without involving the risk that the pressure medium will flow out of the first chamber. Thus, important technical safety advantages and economic advantages are achieved. Moreover, an apparatus according to the present invention can be assembled and filled at normal ambient pressure, which is particularly advantageous, since this permits the use of conventional assembly and filling lines and does not necessitate special pressure provisions.
In a first advantageous elaboration, a container according to the present invention is characterized by the features according to claim 2.
In such an embodiment, in the first position, the control means can move freely relative to the closing member over a selected distance, without the closing member being operated. This means that the volume of the second chamber can vary within selected limits, for instance as a result of a pressure change, without this enabling pressure fluid to escape from the first chamber. Through an activation step, the first and second coupling means can be brought into a coupled second position, such that a change of the volume of the second chamber, in particular an increase thereof, will activate the control means, so that the closing member is operated for at least temporarily clearing the passage opening between the first and third chamber. The container can, for instance, be filled and the pressure control device can be fitted with the coupling means in the first position, so that unwanted release of pressure fluid from the first chamber is prevented, while the container can be made ready for use through the activation step referred to. The activation step can be chosen such that it can be effected by the consumer himself and/or such that it can be carried out by the manufacturer or retailer.
In this embodiment, first and second coupling means are provided which can be brought into a first position in which they are functionally uncoupled, such that the first part can move relatively freely with respect to the second part, without thereby operating the closing member. Only when the first and second coupling means have been brought into a second position, in which they are functionally coupled, can the closing member be moved to an open position by movement of the control means. The activation step then required can, for instance, be obtained by mechanical means, such as the active movement of the first and second part relative to each other, but is preferably obtained in a pneumatic manner by temporarily raising the pressure in the third chamber to above an activation pressure which is preferably at least higher than the control pressure in the second chamber desired during use.
It is preferred that the pressure in the second chamber prior to the activation step is substantially equal to the ambient pressure, at least is approximately equal to 1 bar. This prevents the movable part of the wall from being loaded unduly and protractedly.
The invention further relates to a method for making a container ready for dispensing a fluid under substantially constant pressure, characterized by the features according to claim 6.
With such a method, in a simple manner, a pressure control device can be filled with pressure medium, such as a gas, and subsequently be built together, without involving the risk that pressure fluid flows away undesirably from the first chamber to the environment. In fact, the closing member will keep the first chamber closed at all times, while the control means cannot, at least not yet, open it. Only when the control means have been functionally coupled to the closing member through an activation step can pressure control be provided for by controlled opening and closing of the closing member.
In a first advantageous embodiment, a method according to the present invention is further characterized by the features according to claim 7.
By including the second part in, at least adjacent to, the closing means for the container, and mounting the first part in the container at a slight distance from the second part, they are kept separate in the container prior to use. By further designing the second part to be movable relative to the first part, the pressure control device can be set into operation by coupling the first and second part through the movement referred to. Through cooperation with the closing member, the control means will then provide for the desired internal pressure in the container. In that case, when filling the container, already a pressure can be applied in the inner space, approximately equal to the control pressure in the second chamber. Consequently, prior to the coupling of the first and second part, the control means will be in a neutral position.
In a further advantageous embodiment, a method according to the invention is characterized by the features according to claim 9.
In such an embodiment, the pressure in the inner space of the container is temporarily raised substantially, for instance by introducing an additional amount of pressure gas, in particular CO2, into the headspace of the container, so that the control means are activated and are brought into an actively and functionally coupled position, in communication with the closing member. Since the headspace will normally be relatively small, relatively little gas needs to be additionally introduced, which can be readily absorbed by the beverage, so that the pressure will decrease relatively fast. Thereafter, the opening and closing of the closing member is actively controlled by the pressure control device. It will be clear, incidentally, that it is also possible to obtain the desired pressure increase by reducing the headspace, for instance by deformation of a wall part of the container in the direction of the inner space, or by inflating a balloon-shaped element in the container.
The required activation step can be readily carried out by the manufacturer, for instance by introducing an amount of CO2 or deforming a container wall part directly after filling of the container, during or directly after closure of the container. Also, means may be provided to allow the consumer carry out this activation step, for instance by means of an internal or external gas cartridge, a widget responding to the opening of dispensing means or the like.
As a pressure fluid in an apparatus or method according to the invention, preferably a gas, in particular CO2 or CO2-containing gas, is utilized. However, a different pressure fluid can also be used, for instance a liquid. A pressure fluid can also be obtained in a chemical manner, for instance by bringing together calcium, (bi)carbonate and an acid such as citric acid. Thus, a pressure gas, in particular CO2, is obtained. Many variations thereof are possible. In this connection, for instance the (bi)carbonate or other calciferous product can be stored in the third chamber, at least on the opposite side of the closing member.
Further advantageous embodiments of a container and method according to the invention are set forth in the further dependent claims.